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d: Fix small struct literals that have non-deterministic hash values

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Same issue as the initial commit that addressed PR96153, only this time to fix
it also for structs that are not returned in memory.  Tests have been added
that triggered an assertion on x86_64, however the original test was failing
on SPARC 64-bit targets.

gcc/d/ChangeLog:

	PR d/96153
	* d-codegen.cc (build_address): Create a temporary for CALL_EXPRs
	returning trivial aggregates, pre-filling it with zeroes.
	(build_memset_call): Use build_zero_cst if setting the entire object.

gcc/testsuite/ChangeLog:

	PR d/96153
	* gdc.dg/pr96153.d: Add new tests.
This commit is contained in:
Iain Buclaw 2020-08-25 11:05:57 +02:00
parent 312ad889e9
commit 1db88844a2
2 changed files with 47 additions and 2 deletions
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31
gcc/d/d-codegen.cc
View file

@ -668,9 +668,23 @@ build_address (tree exp)
/* Some expression lowering may request an address of a compile-time constant,
or other non-lvalue expression. Make sure it is assigned to a location we
can reference. */
if ((CONSTANT_CLASS_P (exp) && TREE_CODE (exp) != STRING_CST)
|| TREE_CODE (exp) == CALL_EXPR)
if (CONSTANT_CLASS_P (exp) && TREE_CODE (exp) != STRING_CST)
exp = force_target_expr (exp);
else if (TREE_CODE (exp) == CALL_EXPR)
{
/* When a struct or array is returned in registers, we need to again fill
in all alignment holes. */
if (AGGREGATE_TYPE_P (TREE_TYPE (exp))
&& !aggregate_value_p (TREE_TYPE (exp), exp))
{
tree tmp = build_local_temp (TREE_TYPE (exp));
init = compound_expr (init, build_memset_call (tmp));
init = compound_expr (init, modify_expr (tmp, exp));
exp = tmp;
}
else
exp = force_target_expr (exp);
}
d_mark_addressable (exp);
exp = build_fold_addr_expr_with_type_loc (input_location, exp, ptrtype);
@ -825,6 +839,19 @@ build_memset_call (tree ptr, tree num)
ptr = build_address (ptr);
}
/* Use a zero constant to fill the destination if setting the entire object.
For CONSTRUCTORs, the memcpy() is lowered to a ref-all pointer assignment,
which can then be merged with other stores to the object. */
tree valtype = TREE_TYPE (TREE_TYPE (ptr));
if (tree_int_cst_equal (TYPE_SIZE_UNIT (valtype), num))
{
tree cst = build_zero_cst (valtype);
if (TREE_CODE (cst) == CONSTRUCTOR)
return build_memcpy_call (ptr, build_address (cst), num);
return modify_expr (build_deref (ptr), cst);
}
return build_call_expr (builtin_decl_explicit (BUILT_IN_MEMSET), 3,
ptr, integer_zero_node, num);
}

18
gcc/testsuite/gdc.dg/pr96153.d
View file

@ -20,6 +20,24 @@ Checked!(T, Hook) checked(Hook, T)(const T value)
@system unittest
{
static struct Hook1
{
uint var1 = uint.max;
uint var2 = uint.max;
}
assert(checked!Hook1(12).toHash() != checked!Hook1(13).toHash());
assert(checked!Hook1(13).toHash() == checked!Hook1(13).toHash());
static struct Hook2
{
uint var1 = uint.max;
ushort var2 = ushort.max;
}
assert(checked!Hook2(12).toHash() != checked!Hook2(13).toHash());
assert(checked!Hook2(13).toHash() == checked!Hook2(13).toHash());
static struct Hook3
{
ulong var1 = ulong.max;